A typical platform rocking chair has a pair of curved rocker blocks which are integral with the seat box and ride on a pair of rails which are integral with the platform. Brackets attached to the rails and rocker blocks retain a pair of coil springs at each side of the chair which control the rocking action. Ideally the springs provide an easy, yet restricted rocking action, but when selected for a person of average weight, a heavier person may cause the chair to rock too violently and possibly overturn. Even so, a person of light weight might consider the same rocking chair to be too stiff for comfort.
After a period of use, the springs and/or their brackets may fail due to fatigue or shock. If they do not fail, the spring rate changes to result in excessive rocking action. In any event, the springs eventually become noisy unless lubricated. If lubricated, the lubricant may stain the rug or floor beneath the chair.
Unless the rocker blocks are constructed and positioned with precision, the chair may have a rough rocking action. If the spring brackets are not located with precision or if the coils are not properly adjusted, there may be a discontinuity in the rocking action and/or the unoccupied chair may rest at an angle which is esthetically undesirable.